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//@ run-pass
#![allow(dead_code)]
use std::mem::ManuallyDrop;
union MaybeItem<T: Iterator> {
elem: ManuallyDrop<T::Item>,
none: (),
}
union U<A, B> where A: Copy, B: Copy {
a: A,
b: B,
}
unsafe fn union_transmute<A, B>(a: A) -> B where A: Copy, B: Copy {
U { a }.b
}
fn main() {
unsafe {
let b = union_transmute::<(u8, u8), u16>((1, 1));
assert_eq!(b, (1 << 8) + 1);
let v: Vec<u8> = vec![1, 2, 3];
let mut i = v.iter();
i.next();
let mi = MaybeItem::<std::slice::Iter<_>> { elem: ManuallyDrop::new(i.next().unwrap()) };
assert_eq!(**mi.elem, 2);
}
}
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